fix(plot): don't require Matplotlib if no Window asked

Author: ankostis

graphkit/network.py

@@ -524,8 +524,6 @@ def plot_graph(graph, filename=None, show=False, steps=None,
 
     """
     import pydot
-    import matplotlib.pyplot as plt
-    import matplotlib.image as mpimg
 
     assert graph is not None
 
@@ -610,6 +608,9 @@ def get_node_name(a):
 
     # display graph via matplotlib
     if show:
+        import matplotlib.pyplot as plt
+        import matplotlib.image as mpimg
+
         png = g.create_png()
         sio = io.BytesIO(png)
         img = mpimg.imread(sio)